enum MessageTypeEnum {
  ping(0x00),
  pong(0x80),
  auth(0x01),
  auth_ack(0x81),
  close_socket(0x02),
  close_socket_ack(0x82),

  /**
   * 客户端上行的消息
   */
  message(0x03),
  message_ack(0x83),

  /**
   * 服务端下行的消息
   */
  message_down(0x04),
  message_down_ack(0x84);

  final int value;

  const MessageTypeEnum(this.value);
}
